Managed C++/CLI

27-Jun-07 3:54

I put many control on my form but in the field rate, amount what can I do so that it will be not possible to feed letters characters. With Visual c++ 6.0 MFC there was a class to do that but here, what to do ?

I learn my self

Christian Graus27-Jun-07 12:20

Christian Graus

27-Jun-07 12:20

HAndle the keypress event and reject inappropriate keys.

Christian Graus - Microsoft MVP - C++

"I am working on a project that will convert a FORTRAN code to corresponding C++ code.I am not aware of FORTRAN syntax" ( spotted in the C++/CLI forum )

mikobi27-Jun-07 21:04

27-Jun-07 21:04

PLease Sir,

I am looking how to habdle event in this version, I don't see. CAn you show me how to do it. I see only properties but evetI don't see.

Thanks

I learn my self

mikobi28-Jun-07 22:02

28-Jun-07 22:02

Bring up the Properties editor. Click on the Event button at the top of the Properties editor window- the button with a lightning bolt as a symbol and the editor will show the events associated with the button

mikobi3-Jul-07 6:42

deterministic cleanup in C++/CLI

3-Jul-07 6:42

This Solution to my problem

// Boolean flag used to determine when a character other than a number is entered.
private:
bool nonNumberEntered;

// Handle the KeyDown event to determine the type of character entered into the control.
void textBox1_KeyDown( Object^ /*sender*/, System::Windows::Forms::KeyEventArgs^ e )
{
// Initialize the flag to false.
nonNumberEntered = false;

// Determine whether the keystroke is a number from the top of the keyboard.
if ( e->KeyCode < Keys::D0 || e->KeyCode > Keys::D9 )
{
// Determine whether the keystroke is a number from the keypad.
if ( e->KeyCode < Keys::NumPad0 || e->KeyCode > Keys::NumPad9 )
{
// Determine whether the keystroke is a backspace.
if ( e->KeyCode != Keys::Back )
{
// A non-numerical keystroke was pressed.
// Set the flag to true and evaluate in KeyPress event.
nonNumberEntered = true;
}
}
}
}

// This event occurs after the KeyDown event and can be used to prevent
// characters from entering the control.
void textBox1_KeyPress( Object^ /*sender*/, System::Windows::Forms::KeyPressEventArgs^ e )
{
// Check for the flag being set in the KeyDown event.
if ( nonNumberEntered == true )
{ // Stop the character from being entered into the control since it is non-numerical.
e->Handled = true;
}
}

rockonedge26-Jun-07 21:48

rockonedge

26-Jun-07 21:48

I tried the following code

StreamWriter^ f = gcnew StreamWriter(L"d:\\listfile.txt");<br />
f->Write(L"begin");

expecting a file containing the string "begin" to be created.

To my surprise, only an empty listfile.txt was created. "begin" was not written.
after a few trials, I realized I must explicitly call f->Close() to get "begin" to be written.

is it true that one of the advantages of C++/CLI over c# is that when an object goes out of scope, there is something called deterministic cleanup to close the object, or am I miseducated?

For std::fstream, I surely don't have to call close() explicitly.

Re: deterministic cleanup in C++/CLI

Geo Pa27-Jun-07 3:52

Geo Pa

27-Jun-07 3:52

You can use implicitly dereferenced variables. These variables use the Resource Acquistion Is Initialization (RAII) principle to do their clean up. Also, these variables have the same limiitations as automatic variables:

StreamWriter f(L"D:\\listfile.txt");
f.Write(L"begin");
...
// When "f" goes out of scope, it will be deterministically disposed of.

In order to obtain a tracking handle to an implicitly dereferenced variable, you must prefix it with "%".

byte C# to C++

C#Coudou26-Jun-07 19:22

C#Coudou

26-Jun-07 19:22

Whats wrong with my C++ code, it gets me an error.
How to use byte array in C++ by the way?

C# code:

int data_size = 146000;
int data_loop = 4096;
byte[] data_sent= new byte[data_size];
Random rnd = new Random();
rnd.NextBytes(data_sent);

for (int x = 0; x < data_size; x++)
if (data_sent[x] == 0x3f){
data_sent[x] = 0;
}

C++ code:

int data_size = 146000;
int data_loop = 4096;
Byte[] data_sent = gcnew Byte[data_size]; //Gets me error
Random^ myrandom = gcnew Random;
myrandom->NextBytes(data_sent);
for (int x = 0; x < data_size; x++)
if (data_sent[x] == 0x3f){
data_sent[x] = 0;
}

note: the c# is working and compiled but the c++ code stuck me from that error. Confused | :confused:

******************************
I just want to
know everything

Re: byte C# to C++

C#Coudou26-Jun-07 19:39

C#Coudou

26-Jun-07 19:39

I got it already. thanks

******************************
I just want to
know everything

Network speed detection

C#Coudou26-Jun-07 18:36

C#Coudou

26-Jun-07 18:36

Bros,

How to code the network speed detection?
What i mean is i want to detect the upload and download using clickbutton. When I press a button it will show to textbox1 the upload speed and textbox2 the download speed.
example:
TextBox1 = 42 kbps
TextBox = 54 kbps

Is anybody here how to do that? Much better if you can give me some links for basic.

Thanks in advance.

******************************
I just want to
know everything

Re: Network speed detection

Paul Conrad14-Jul-07 13:41

Paul Conrad

14-Jul-07 13:41

Send some packets of data of certain size (you decide how much data you want to transfer), see how long it takes to go up and come back, then report the results in the textbox.

"Any sort of work in VB6 is bound to provide several WTF moments." - Christian Graus

ConnectionString

mikobi26-Jun-07 4:53

26-Jun-07 4:53

I am using Sql SErver 2000 Database and I begin to work with Visual c++ Net 2005;

How to to write SqlCommand::Connection to connect to SQl server 2000 in Visual c++ net 2005

I learn my self

led mike26-Jun-07 5:26

led mike

26-Jun-07 5:26

I see you have lots of Database development questions. Lucky for you there are a massive number of Database Articles here on CodeProject. Use the Navigation mechanisms on the site to find the Database Articles and look through them. I am sure the information you seek is in there.

Mark Salsbery26-Jun-07 5:55

Mark Salsbery

26-Jun-07 5:55

In addition to led mike's reply, I think it's important to consult the documentation for the
platforms/systems/etc. that you're wanting to develop for.

For example, to connect to SQL Server, you'll probably want to use the SQL Native Client.
Connection string info can be found here: Using Connection String Keywords with SQL Native Client[^]

Mark

"Go that way, really fast. If something gets in your way, turn."

mikobi27-Jun-07 5:37

27-Jun-07 5:37

Mark Salsbery27-Jun-07 6:35

Mark Salsbery

27-Jun-07 6:35

Does that work? Smile | :)

Mark

"Go that way, really fast. If something gets in your way, turn."

mikobi27-Jun-07 21:06

27-Jun-07 21:06

Yes, very well

Query with parameters

mikobi26-Jun-07 3:36

Re: Query with parameters

26-Jun-07 3:36

I am using Visual C++ NET 2005.

I want to know how to execute a query with parameters in my program

I learn my self

mikobi27-Jun-07 5:34